Process of making firm foundations in the ground for piles, tubed shafts, and the like.



A 0. WILHELMI.

rnocEss OF MAKING FIRM FQUNDATIONS IN THE GROUND FOR PILES, TUBED SHAPTS,

' AND THE LIKE! APPLICATION PILEDIIDEO. 80, m2.

Patented Aug. 11, 1914 UNITED STATES PATE ToFIiICE.

omo WILHELHI, ortucnmm, swzrznnmnn, kssienon or ONEQHALF 'ro INTER- .NATIONALE .SIEGWARTBALKENGESELLSCHAFT, A FIRM.

Pnocnss' orfntame FIRM roumm'rrons IN THE GROUND non PILES, TUBED To all whom it may concern:

Be it known that I, O'r'ro WILHELMI, a subject of the Emperor of Germany, and residing at "Lucerne, Switzerland, have invented certain new and useful Improvements in Processes of Making Firm Foundations in the Ground for Piles,Tubed Shafts, and. the like, of which the following 1s a specification.

the explosive action may be successively utiliz ed for forming the space for the shaft of the pile itself having one or more enlarged portions. i

T 'The mode of carrying m process into practice will now be describe by way of example with reference to the accompanying drawings, wherein Figures 1 and 2 are vertical sections showing the formation of a concrete pile before and after employing the process according to this invention; Fig. 3 is an elevation showing a finished concrete pile having sev eral enlarged portions; Fig. 4 is an elevation partly in section, illustrating a mode of making a concretepile in which the preliminary tube first driven into the ground isleft there as a permanent mold; Figs. 5 and Gare elevation and longitudinal vertical section, respectively, showing devices by means of which the action of the explosive. can be regulated; Fig. 7 shows a concrete base on which a ready-made short pile has been sub sequently placed.

In maklng the foundations of concrete piles according to this invention, a hole for the explosive is first formed, said hole being suited to. the dimensions of the pileshaft. For this purpose, as shown in Fig. 1, the mold for the hole for the explosive, the

' pipe 9 is driven into the ground, and if it v is to be used again, it is loosened and drawn SHAFTS, THE LIKE.

p pecificatlon of Letters Patent. Application filed December 30, 1912. Serial No. 739,402

Patented Aug. 11, ieia.

so far outthat it'cannot be injured by the explosion. The explosive charge 2 is covered by a quantity of soft or liquid concrete and is then-ignited by means of the fuse 10 and, m consequence of its explosive action, the surrounding ground is forced apart and a hole or cavity 12 is formed, (Fig. 2') into whichthe liquid concrete above it at once rushes or flows. If necessary, the concrete 'ma then be consolidated in the hole 12 by mold, where the pipe 6 forms a good rein- I forcement, and is firmly embedded in the concrete of the broad base 14 by its ends which are torn into lugs or strips 13 by the explosion, The explosive charge must be protected from premature ignition owing to the concrete mass, which is subsequently filled into the bore hole, or falling stones or the like, and .the column of concrete above the charge must be protected from being severely. pressed upward by the explosion and possibly driven out of the pipe. To this end, the explosive charge 2 may be placed in a, cage 15 (Figs. 1 and 5) which is preferably formed of two plates 16, 17 located one above the otherat certain distances apart and haying intermediate side pieces 18. A cage 15, as shown in Fig. 6, of ferro-concrete may also be employed, in which the plates 16, 17 are formed of concrete and the intermediate pieces are constituted by coiled .iron reinforcement 19. The upper plate 16 or 16 restrains the upward pressure. As the explosive charge rests on the 'lower plate 17 or 17 and the sides are wholly or partially open, the force of the explosion is mainly directed downward and laterally. The downward pressure compresses the ground below the cage and renders it more stable, and the increased lateral pressure makes a wider hole 12 and a larger base 14 is formed than is the case when the explosion is unrestricted. As shown in Fig; 7,

i a previously prepared short pile 14' is subsequently placed upon the concrete base 14.

\Vhat I claim is 1. A process of making firm pile foundations in the ground, consisting in making a hole in the ground, placing the explosive charge upon the bottom of this hole, filhng the latter with grout, exploding the charge and forming thereby an enlarged recess into which the grout automaticallydescends and fills it.

2. A process of making fi rm pile foundations in the ground, consisting in makin a hole in the ground, lining the hole w1th metal tubes, placing an explosive charge upon the bottom of said hole, connecting a protected fuse with said charge, filling the hole with grout, exploding said charge and forming thereby an enlarged recess into in presence of two witnesses.

OTTO WILHELM I.

grout automatically descends and Witnesses OHARLOTIE METzNER,' Amman) MEYER.

thereby an enlarged recess into 

